Computation of microstructural stresses in sintered UO2 fuel

Abstract

The objective of this work is to employ a finite element model at the microstructural level (mesoscale) to investigate the stress and strain distributions in sintered UO2 fuel pellets. The model makes use of a finite element discretization at the scale of individual grains in order to capture the non-uniform deformation within the microstructure. The anisotropic material response of the underlying crystal lattice in each grain, as well as the interaction of the grain with its neighbors, influences the local deformation and hence the strain and stress distributions. Such simulations provide a valuable tool in identifying locations of high stress and strain, which can be the sites for potential crack initiation.